This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Elevated total IgE and specific IgE to allergens from diverse sources including cat and house dust mite (HDM) have been demonstrated in patients with atopic dermatitis (AD). Improvement of eczematous lesions has been reported when patients are admitted to the hospital, which represents an "allergen-free" environment. Severe clinical disease in AD patients has been attributed to suppression of the immune response or immune dysregulation. We have recently demonstrated that the immune response to allergens is altered at both the B-cell and T-cell level in allergic patients with AD. We will test the hypothesis that allergen avoidance in subjects with IgE ab to common allergens is associated with improvement of skin condition and changes in the immune response to allergens derived from HDM and cat. Serum antibodies (IgG and IgE) and T cell responses to common allergens and allergen-derived peptides will be monitored at weekly intervals (3 weeks maximum) in AD patients who receive a complete allergen avoidance regimen in a hospital environment. Detailed analysis of in vitro T cell responses will include measurement of allergen-stimulated proliferation and cytokine production, expression of cell surface markers by flow cytometry and enumeration of different T cell subsets. Data will be compared at each time point within each individual in order to determine changes which occur during allergen avoidance. Results will also be compared between groups of AD patients with and without IgE ab to common allergens. Statisical tests will include student's t test, cross-validated linear discriminant analysis, and linear regression analysis.